she said she had a guy in the past, he arated the back yard(total shade, poor drainage) and since he aerated the moss had got progressively worse. is this possible? does aeration in such an environment cause moss?
NO>>>>>Moss in yards has been a common complaint this spring. It occurs in sun or shade, alkaline or acidic soils and in wet or dry sites. Moss is very adaptable and can grow in difficult conditions. In poor sites, the moss moves in as the grass dies out.
The easiest way to eliminate moss is to rake it out of the affected areas and alter the conditions responsible for its presence. If moss is occurring in a shaded area, consider planting the area with shade tolerant grasses such as creeping red fescue, chewings fescue or hard fescue. If the fine-leafed fescues have failed, perhaps it is time to consider alternative shade tolerant groundcovers rather than grass. Surrounding trees may need to have their lower limbs removed or the crown of the tree thinned to allow more light penetration. Remove unnecessary shrubby undergrowth as well.When moss occurs in a sunny location, consider fertilization practices. Even low-maintenance lawns need one or two fertilizer applications a year to grow well. In some cases the soil may be compacted and need aeration as well. Soil testing will provide the soil pH. Grass grows optimally at a pH of 6.8 to 7.2 which is close to neutral. Many people automatically assume the soil is acidic when moss occurs and want to add lime.